Hydraulic actuating means



DEC. 8, 1936. w NQBLE. 2,063,882

HYDRAULIC ACTUATING MEANS Original Filed May 4, 1927 2 Sheets-Sheet 1.MWfQi Dec. 8, 1936. w 2,063,882

HYDRAULI C ACTUAT ING MEANS Original Filed May 4, 1927 2 Sheets-Sheet 2t 61 I Y attomnuq Patented Dec. 8, 1936 UNlTED STATES PATENT OFFICEGeneral Motors Corporation,

Detroit, Mich., a

corporation of Delaware Refiled for abandoned application Serial No.

188,855, May 4, 1927. 13, 1935,

15 Claims.

This invention relates to hydraulic valve actuating means, such as valvegears of the type described in patent to Warren Noble and Leon V.Pittman, No. 1,691,896 of November 13, 1928, and is refiled for theabandoned application Serial No. 188,855, filed May 4, 1927, wherein apuppet valve is described as operated by a plunger through the medium ofan oil column trapped in an actuator chamber, and valvular means areprovided for controlling the inlet of oil to said chamber and the reliefof air and oil from the chamber during peri-' ads when the puppet valveis closed, said valvular inlet and relief means being illustrated in theform of automatic valves controlled by pressure in the said actuatorchamber.

The said valve gear admits of the use of mechanically operated relief orinlet valves for the actuator chamber, or both of the said valves may bemechanically operated; and has also for its object to provide for themechanical control of flow through the actuator chamber.

Still further the said invention has for its object to provide for theeffecting of such mechanical control fiow through the chamber by thecamshaft or mechanism operating the actuator plunger or plungers as thecase may be.

Still further objects or advantages subsidiary or incidental to theaforesaid objects, or resulting from the construction or operation ofthe invention as it may be carried into effect, will become apparent asthe said invention is hereinafter further disclosed.

In carrying the said invention into effect, I may provide a hydraulicvalve gear wherein a puppet valve has its stem exposed to the interiorof a hydraulic fluid-confining actuator chamber in which hydraulic fluidis subjected to the action of a cam-operated plunger which effects,through the fluid in said casing, the actuation of said puppet valve;together with a check valve opening from a hydraulic fluid manifold tosaid actuator chamber, and a relief valve opening from said actuatorchamber under the influence of the cam by which said plunger isoperated, but at a time when the plunger is dwelling on the base circleof the said cam, whereby, in such open position of the relief valve,flow from the said manifold through the actuator chamber is permitted.All of which is more particularly described and ascertained hereinafter,by way of exampleyhaving reference to the accompanying drawings,wherein:

Figure 1 is a transverse section of part of an engine cylinder headstructure having incorporated therein valve actuating means embodyingthe said invention.

This application March Serial No. 10,894

Figure 2 is a fragmentary section taken on the line 2 -2 of Figure 1.

Figure 3 is a fragmentary detail section taken on the same plane asFigure 1, illustrating a modified arangement of actuator chamber inletvalve.

Figure 4 is a fragmentary section taken on the line 4 4 of Figure 5through theinlet and exhaust valve actuator chambers of an engineshowing a modified arrangement of fiow control in which the relief valveis common to both actuator chambers.

Figure 5 is a vertical section of the same taken on the line 5 -5 ofFigure 4.

Figure 6 is a transverse section taken on the line 6 -6 of Figure 4.

Similar characters of reference indicate similar parts in the severalfigures of the drawings.

Referring first to Figures 1 and 2, cylinderhead structure I is shownhaving a puppet valve 2 mounted therein and maintained seated by thevalve spring 3, the said cylinder head structure including an uppervalve actuator structure 4 chambered to provide a valve actuator chamber5 to the interior of which the upper end of the stem of the puppet valve2 is exposed. This chamber is intended to contain a hydraulic fluid,such as oil, which acts as a means of transmitting motion to the stem ofthe valve 2 from an actuator plunger 6, one end of which plunger is alsoexposed to the interior of said actuator chamber 5 and the other end ispressed against a cam I by a plunger spring 8 so that the said plungerwill follow the contour of the said cam.

9 is a fluid manifold preferably supplied with oil under pressure, and I0 is a check valve adapted to open from the said manifold into theactuator chamber 5 when pressure in the manifold 9 exceeds pressure inthe actuator chamber to an extent suflicient to overcome the resistanceof the check valve spring II. The check valve is indicated as beinghoused in a casing I! having a port l3 communicating with the manifold,and a further port I4 communicating with the actuator chamber to ,permitthe required flow from the manifold to the actuator chamber when thecheck valve is open. This casing is held in position on suitablyprovided seats by the plug I5 in the top of the actuator structure.

The actuator structure 4 is also shown as housing a further plunger itwhich forms a relief valve as will be explained, this plunger having itslower end also bearing on the cam l, by reason of the action of therelief valve spring I! confined between the said plunger and a plug 18in the upper end of the said actuator structure 4, the said plunger i6being so arranged radially of the cam that its operation alternates withthat of the plunger 6.

The plunger I6 is tubular and has an outlet passage i9 at its lower endand an inlet passage 20 towards its upper end, which inlet passage opensfrom an annular groove 2i in the said plunger [6 adapted to registerwith a relief port 22 of the actuator chamber 5 when the said plunger I6is raised to a suflicient extent by the lobe of the cam 1. This reliefport 22 opens from a high point or region of air accumulation in theactuator chamber 5.

Arranged within the tubular plunger i6 is a spring pressed check valve23 permitting outward or downward flow only through the said plunger.

As previously explained, rotation of the cam 1 effects intermittentlifting of the plunger 6 and the consequent operation of the puppetvalve 2, and during such time as the valve 2 is open, and the plunger 8in a position other than dwelling on the base circle of the cam, fluidin the actuator chamber 5 is subjected to considerable pressure so thatthere is no tendency of the check valve ID to open. During this pressureperiod the plunger i6 dwells on the base circle of the cam so thattheannular groove 2i thereof and the relief port 22 of the actuatorchamber do not register, the hydraulic fluid, therefore, beingeffectively confined in the actuator chamber.

After the lobe of the cam passes beyond the actuator plunger 6 inwhichever direction the said cam may rotate, it eventually raises theplunger i6 until the annular groove 2| thereof coincides with the reliefport 22 of the actuator chamber, but at this time it will be understoodthe plunger 6 again dwells on the base circle of the cam, and. thepuppet valve is closed so that there is then no pressure exerted on thefluid in the actuator chamber. As a consequence, slight pressure offluid in the manifold 9 will lift the check valve I0 and result in flowtaking place through the actuator chamber and therefrom by way of the Irelief port 22 through the hollow interior of the plunger i6 and theoutlet passage IS. The check valve 23 offers but little resistance tothis flow which is easily overcome.

The said flow of oil through the actuator chamber during the period ofpuppet valve inaction is effective both to scavenge air from the saidchamber and to ensure a replenishing of oil therein to compensate forany loss by leakage or otherwise, whereby a complete filling of thechamber with oil prior to the ensuing valve actuating movement of theplunger 8 is ensured as required to ensure proper translation of plungermovement into puppet valve movement.

If thought necessary or desirable, means may be provided for thepositive operation of the inlet check valve l0, such as to overcomesticking, and in Figure 3 the plunger i6 is shown as being equipped witha projecting member 24 adapted to engage the stem of the said checkvalve l0 when the said plunger i6 is raised by its cam, therebypositively opening the said check valve.

The relief valve or plunger i6 may not necessarily be limited to thecontrol of flow through a single actuator chamber as in the case of thearrangement shown in the Figures 1, 2 and 3, but may be used inconnection with more than one actuator chamber as shown in Figures 4, 5and 6, wherein 5 and 5 represent respectively n... marmchambers of theinlet and exhaust valves l and 2 of an engine cylinder, whereintheexhaust valve operates immediately prior to the operation of theinlet valve and a relatively considerable period of time elapses betweenthe closing of the inlet valve and the opening of the exhaust valve.During such period both valves are inactive and flow through both of theactuator chambers may simultaneously take place.

Taking advantage of this fact, only one plunger.

i6 is utilized for both actuator chambers, this plunger l6 beingsituated between the actuator plungers 6 and 6 which are operated bythe'inlet and exhaust cams I and 1 of the camshaft 25. The reliefplunger i6 is operated by a cam 26 intermediate of the cams i and l saidcam 26 having its lobe interposed between the base circles of the saidcams I and 1 as clearly shown in Figure 6, whereby it will, when raised,open the relief ports 22 and 22 The described arrangements afford a verysimple means of effecting the positive control of air elimination andoil replenishing in hydraulic actuating means such as hydraulic valvegears, and admit of many variations of design and part arrangement incarrying out the principles involved; and the invention may, therefore,be developed within the scope of the following claims without departingfromthe essential features of the said invention, it being desired thatthe specification and drawings be read as being merely illustrative andnot in a-limiting sense, except as necessitated by the prior art.

I claim:

1. In combination with an inlet and an exhaust valve of an enginecylinder, an individual hydraulic fluid casing for each valve to theinterior of which the stems of the valves are exposed for hydraulicoperation, non-retum hydraulic fluid supply means for both of saidcasings, a normally closed air bleed valve opening from a region of airaccumulation in each of said casings, said valve being common to both ofsaid casings, timed mechanism imposing pulsating pressure alternately onfluid in said casings for the alternate actuation of said valves, andmeans opening said bleed valve during periods of substantial zeropressure in both of said casings.

2. In combination with an inlet and an exhaust valve of an enginecylinder, an individual hydraulic fluid casing for each valve to theinterior of which the stems of the valves are exposed for hydraulicoperation, non-return hydraulic fluid supply means for both of saidcasings, a normally closed air bleed valve common to both of saidcasings and opening from regions of air accumulation therein, timedmechanism for imposing pulsating pressure alternately on fluid in saidcasings for the alternate actuation of said valves and for operating ableed valve, said bleed valve being opened by a part of said timedmechanism during the period of substantial zero pressure in both of saidcasings.

3. In combination with an inlet and an exhaust valve of an enginecylinder, an individual hydraulic fluid casing for each valve to theinterior of which the stems of the valves are exposed for hydraulicoperation, non-return hydraulic fluid supply means for both of saidcasings, a normally closed air bleed valve opening from regions of airaccumulation in both of said casings, said valve being commonto both ofsaid casings, and timed mechanism imposing actuating impulsessuccessively on the fluid of said exhaust valve casing, on the fluid ofsaid inlet valve aoeaaaa casing and on said bleed valve whereby saidbleed valve is opened during the period following the operation of saidinlet valve and prior to the succeeding operation of said exhaust valve.

' plunger for imposing intermittent pressure on fluid in said casing, anoutlet valve opening from a region of air accumulation in said casing,said outlet valve being spaced from said plunger and separate therefrom,and a single means for operating said plunger and said outlet valve,said means moving said plunger and said outlet valve alternately. v

6. In a hydraulic actuator device, a hydraulic fluid casing, a plungerimposing intermittent pressure on fluid in said casing, an outlet valveopening from a region of air accumulation in said casing, said outletvalve being spaced from said plunger, a single means for operating saidplunger and said outlet valve, a fluid supply manifold, a non-returnvalve opening from said manifold to said casing, and means carried by aportion of said outlet valve and moved therewith for positively openingsaid non-return valve.

7. In a hydraulic actuator device, a hydraulic fluid casing, a fluidsupply manifold, a non-return valve opening from said manifold to saidcasing, a plunger for imposing intermittent pressure on fluid in saidcasing, an outlet valve opening from a region of air accumulation insaid casing, said outlet valve being spaced from said plunger andseparate therefrom, and a common cam alternately operating said plungerand said outlet valve.

8. In a hydraulic valve actuating means, the combination with a puppetvalve stem, of a hydraulic fluid casing to the interior of which saidstem is exposed for hydraulic operation, a nor- .mally closed air bleedvalve opening from a region of air accumulation in said casing, a fluidsupply manifold, a non-return valve opening from said manifold to saidcasing, a plunger and means for operating the same for imposingpulsating pressure on fluid in said casing for the actuation of saidvalve stem, said air bleed valve being spaced from said plunger, meanspositively opening said bleed valve intermediate periods of pressure onfluid in said casing and means operated by the movement of said bleedvalve for posi-- tively opening the non-return valve.

9. In a hydraulic valve actuating means, in combination with a puppetvalve stem, a hydraulic fluid casing to the interior of which said stemis exposed for hydraulic operation, a fluid supply manifold, anon-return valve opening from said manifold to said casing, a plungerfor imposing pulsating pressure on fluid in said casing for theactuation of said valve stem, and a normally closed air bleed valveopening from a region of air accumulation in said casing, said bleedvalve being spaced from said plunger and separate therefrom, and acommon cam for alternately operating said plunger and said bleed valve.

10. In a hydraulic valve actuating means, in combination with a puppetvalve stem, of a hydraulic fluid casing to the interior of which saidstem is exposed for hydraulic operation, a fluid supply manifold, anon-return valve opening from said manifold to said casing, acam-operated plunger imposing intermittent pressure on fluid in saidcasing for the actuation of said valve stem, a cam-operated outlet valveopening from a' region of air accumulation in said casing, means carriedby a portion of said valve for positively operating said non-returnvalve. and a common cam alternately operating said plunger and saidoutlet valve.

11. In combination with an inlet and exhaust valve of an enginecylinder, separate hydraulic fluid casings for each valve into which thestems of the valves project for actuation, means for periodicallyimpressing pressure on the fluid to actuate the valves, fluid supplymeans for each casing, a bleed valve common to both hydraulic casingsand operated by timed means between pressure actuations.

12. In an internal combustion engine having inlet and exhaust valvesoperated by separate fluid columns inclosed in casings which haveplungers to impress actuating pressure thereon periodically, fluidsupply means connected to the casings to keep them full of fluid, ableed valve common to both casings to bleed both air and a smallquantity of oil, and timed mechanism to operate said bleed valve duringinoperative plunger periods.

13. In an internal combustion engine having hydraulic operating systemsfor intake and exhaust valves, and a source of fluid supply therefor, ableed valve common to said operating systems to bleed therefrom air andoil to keep a solid fluid column, and timed means to actuate said bleedvalve during periods of low pressure in the hydraulic systems.

14. In a hydraulic actuator device, means for bleeding air from ahydraulic fluid casing wherein fluid is subjected to pulsating pressurecomprising a channel in the casing from a point of air accumulation, aplunger in the casing, an opening in the plunger that coincides with thechannel in raised position, a second channel longitudinal through theplunger connected with the opening and a spring biased valve within theplunger near the lower end of the plunger channel to control the flowfrom the lower end of the channel, and actuating means to raise theplunger at periods of low pressure in the casing.

15. In hydraulic valve actuating .means, in combination with a puppetvalve stem, a hydraulic fluid casing to the interior of which said stemis exposed for operation, a fluid supply manifold, a non-return valveopening from said manifold to said casing, a cam operated plungerimposing intermittent pressure on fluid in said casing for the actuationof said valve stem, a plunger outlet valve opening from a region of airaccumulation in said casing whose axis is set at an angle to theoperating plunger, and a single cam operating both plungers alternatelywhereby when the actuating plunger is moved the bleed plunger will be inclosed position and when the bleed plunger is moved to open position theactuating plunger will not be impressing pressure upon the fluid.

' WARREN NOBLE.

